Overview

Before civilization began to impact the human life cycle approximately 10,000 years ago, human beings had high birth and death rates. Today the world is in the midst of a demographic transition — a transition to low birth and death rates — as the ability to control both disease and reproduction increases. Along the way, between these extremes, populations go through an intermediate period of continued high birth rates, combined with low death rates, resulting in a population explosion.

Because countries span a continuum along this transition, looking at the present demographics of countries around the world provides an opportunity to look forward or backwards in time: a post-transition country can get a glimpse of a situation resembling its own past from countries still in transition, and a transitional country may get a hint of its demographic future from countries that are further along the continuum.